Traditional methods of fabricating composite structures include assembling cured composite components using fasteners or adhesive. The use of fasteners requires special drilling equipment for forming fasteners holes in the composite components to be joined. In addition, the process of installing individual fasteners in a plurality of fasteners holes is a time-consuming and labor-intensive process. Furthermore, the plurality of fasteners in a structural assembly adds weight which detracts from the performance capability of weight-sensitive structures such as aircraft.
Assembling a composite structure by bonding together composite components using adhesive may limit the use of the structure to applications that are not required to carry primary loads. Assembly techniques that rely on fasteners and/or adhesive may necessitate positioning of the mating (e.g., faying) surfaces of the individual components within relatively tight geometrical tolerances. The requirement for tight geometrical tolerances increases manufacturing cost and adds to manufacturing time.
Forming composite structures that are relatively large and/or which have complex geometries may present additional challenges. For example, the traditional process of curing a layup for a large composite structure may require the availability of a large autoclave for uniformly applying heat and pressure. Unfortunately, large autoclaves have high initial construction costs and high operation and maintenance costs, and may present limitations in producing composite parts at a high production rate. Composite structures that have complex geometry traditionally require separately laying up and curing individual components, and then fastening and/or adhesively bonding the components together, with the associated drawbacks mentioned above.
As can be seen, there exists a need in the art for a method of fabricating a composite structure that limits or avoids the use of fasteners and adhesive, and which allows the fabrication of composite parts that are relatively large and/or which have complex geometries.